The present invention generally relates to a method and an apparatus for making a liquid drop fly to form an image by generating a bubble in a liquid, and more particularly to a method and an apparatus for making a liquid drop fly to form an image by generating a bubble in a liquid without using a nozzle.
Conventionally, a method and apparatus for making a liquid drop fly to form an image by generating a bubble in a liquid has been proposed in Japanese Patent Publication No. 61-59914. This method and apparatus is respectively often referred to as a liquid jet recording method and a liquid jet recording head. In the liquid jet recording method and the liquid jet recording head, a liquid, such as ink, provided in a flow path connected to a nozzle is heated and a film boiling is formed in the liquid. Then a bubble is generated by the boiling film in the liquid and a liquid drop is jetted from the nozzle by propulsion based on the rapid growth of the bubble. The liquid drop jetted from the nozzle flies to a recording sheet so that an image is formed on the recording sheet.
The conventional apparatus as described above comprises the nozzle from which the liquid drop is jetted. A diameter of an orifice formed on the nozzle is vary small, for example, 60 um. Thus, it is difficult to accurately form the nozzle. In addition, the nozzle can be clogged by dust which is generated in a system for supplying a liquid (ink), impurities in the liquid and so on. Then, when the nozzle is clogged by the dust and so on, the liquid drop can not fly regularly from the nozzle.
A conventional liquid jet recording head not using the nozzle is also proposed in Japanese Laid-Open Patent Application Nos. 51-132036 and 1-101157. In the liquid jet recording head disclosed in Japanese Laid-Open Patent Application No. 51-132036, a bubble is generated and grows in ink. When the grown bubble is exploded and the ink returns to the original condition, an ink drop is generated and flies. According to the conventional liquid jet recording head as described above, when the bubble is exploded, the ink is scattered like a mist. Thus, the quality of an image formed on the recording sheet is deteriorated by the scattered ink mist.
On the other hand, in the liquid jet recording head disclosed in Japanese Laid-Open Patent Application No. 1-101157, a small heater element provided in ink is rapidly heated so that the ink is rapidly boiled and the ink mist is generated. Then the ink mist flies to the recording sheet and an image is formed on the recording sheet. According to the conventional liquid jet recording head as described above, the image is formed by the ink mist on the recording sheet so that it is difficult to form a clear image on the recording sheet.